The present invention relates to disk playback devices, such as compact disk players.
1. Field of the Invention
The disks to be described below are those having music information recorded thereon, whereas such disks may be those having English conversation or other programs recorded thereon.
2. Description of the Related Art
With common disk playback devices, a break occurs in the sound reproduced from disks during a change from one disk played back to another disk. This gives discomfort to the user who is desirous of listening to the reproduced sound without any interruption. In view of such experience, playback devices have been proposed which permit a change of disk without a break in the reproduced sound (see JP-A No. 69263/1997).
The proposed device is of the so-called autochanger type, which has a stacker 8 for accommodating a plurality of disks D as arranged one above another as shown in FIG. 8. The disk D is delivered from the stacker 8 by a change hand 81 of a disk changer mechanism 80. The disk D is placed on a turntable 73, and a reproduction signal is retrieved from the disk by a pickup 2 which is slidable radially of the disk. With an error signal taken out by an RF amplifier circuit 20, the reproduction signal is stored in a memory 5 by a system controller 82. Since the signal is written to the memory 5 at a rate which is always higher than the reading rate, a predetermined quantity of data is stored in the memory 5 at all times.
For a change of disk, the system controller 82 operates the disk changer mechanism 80, which places the disk on the turntable 73 into the stacker 8 and automatically takes out another disk from the stacker 8. During the changing procedure, the data remaining in the memory 5 is reproduced with no break occurring. in the reproduced sound.
Portable disk playback devices have been proposed in recent years. With reference to FIG. 9 showing such a device, a base frame 70 for placing a disk thereon has a closure 7 pivoted to one side portion thereof and positionable over the disk. The disk on the playback device needs to be replaced by another one by the user himself. However, the user, while listening to the reproduced sound, is unable to recognize when to change the disk because he has no means to detect when the playback of the disk is about to terminate.
Such a portable disk playback device has also been proposed which is adapted to temporarily store the sound reproduced from the disk in a memory 5 and output the sound a predetermined period of time thereafter (see JP-B No. 85980/1993). The device has a vibration proof function and is adapted to correct skipping of sound. As shown in FIG. 6, the device has memory means 55 for storing the sound reproduced from the disk in the order of addresses, and sensor means 56 for detecting discontinuity of time code of the reproduced sound, i.e., inaccurate reproduction. Upon the sensor means 56 detecting a discontinuity in the time code, the pickup 2 is moved back to a position on the disk before the occurrence of the discontinuity, with writing to the memory means 55 suspended during the movement of the pickup 2. The writing to the memory means 55 is resumed after the pickup 2 has been moved. The portion of skip is not stored in the memory means 55, permitting a speaker 91 to output the reproduced sound without any break.
The present invention has been conceived based on the idea that even portable disk playback devices can be adapted for a disk change without an interruption of sound reproduction or with a shortened duration of interruption when the device is provided with means for notifying the user of disk change timing, utilizing memory means for temporarily storing the sound reproduced from the disk.
When the user changes from one disk to another, the user is desirous of suspending playback of the current disk and quickly playing back the next disk replacing the first disk, or the user is desirous of playing back the next disk after the current disk has been completely played back to the last. In the former case, however, the playback data of the first disk is continuously output from the memory 5 although disk playback is suspended during continuous playing-back operation. This gives discomfort to the user who is desirous of promptly playing back the next disk. Alternatively in the latter case, it is desirable to output the playback data of the next disk after the playback data of the first disk has been completely output.
An object of the present invention is to make different the timing at which the playback data of a disk replacing the preceding disk is output, when playback of the preceding disk is suspended and when the preceding disk is played back completely to the last, as desired by the user intending to change the disk.
The disk playback device of the invention comprises a memory 5 and erase means connected to the memory 5 for erasing data remaining in the memory 5.
Provided inside the device are flag generating means for producing different flag values in a first case wherein end sensor means detects the playback end of a disk to terminate playback of the disk and in a second case wherein the user manipulates one of manual keys 31 to terminate the playback, discriminating means for judging whether termination of disk playback is the, first case or the second case from the flag value, and memory control means connected to the discriminating means and operable in the first case to input to the memory 5 playback data of another disk replacing the above disk as continued from the data remaining in the memory 5, the memory control means being operable in the second case to input to the memory 5 the playback data of another disk replacing the first-mentioned disk after the data remaining in the memory 5 is erased by the erase means.
In the first case, the user is desirous of playing back the disk completely to the last. The data of the second disk replacing the preceding disk is output from the memory 5 subsequent to the output of the data of the preceding disk from the memory 5. The disk sound reproduction involves no interruption even during the change of disk, or the duration of interruption is shortened.
On the other hand, in the second case wherein the user intentionally discontinues disk playback, the user is desirous of playing back the next disk instead of the disk currently being played back. In this case, the data remaining in the memory 5 is first erased, so that the playback data of the disk replacing the current disk is output without waiting for complete output of data of the preceding disk. In the second case, therefore, the playback data of the subsequent disk is output promptly.
Thus, the timing at which the playback data of the disk subsequent to a disk change can be altered as desired by the user.